After a few months in Quemados, Lazear, together with Walter Reed (1851-1902), James Carroll (1854-1907) and Aristides Agramonte (1869-1931), participated in a commission studying the transmission of yellow fever, the Yellow Fever Board. During his research at Camp Colombia, he discovered that mosquitos transmitted this disease. A portion of his study, though, had been conducted on himself: without telling his colleagues, he had allowed himself to be bitten by yellow fever-infected mosquitoes and died of the disease at age 34. A dormitory at Johns Hopkins University was named after him in honor of his sacrifice, as was the chemistry building at Washington & Jefferson College, Lazear's alma mater.